Red Flip-Chip LED Architecture for Multi-Color COB Packaging
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Solution Overview
Problem
Existing flip chip LEDs primarily emit blue light, limiting their application in multi-color lighting scenarios, and there is a need for LEDs with architectures compatible with existing LED packages to simplify assembly and optical/thermal design.
Innovation Solution
Development of flip chip LEDs emitting yellow, amber, and red wavelengths, particularly red wavelengths from 550 to 650 nm, using AlInGaP active material bonded to transparent carriers like sapphire or glass, with electrodes positioned along a common surface and isolated electrically, integrated into chip-on-board packages with phosphor materials for multi-color output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If blue flip chip LEDs are used, then the LED architecture is established for white LED applications, but multi-color applications are not satisfied
Solution Approach 1:
The patent develops red flip chip LEDs with the same fundamental architecture as blue flip chip LEDs, enabling a single package design to accommodate multiple LED types (blue and red) for multi-color applications. The active material layer composition is adjusted (AlInGaP for red vs. GaN for blue) while maintaining the overall device structure, allowing universal packaging and simplified assembly processes.
2Adaptability or versatility
If red flip chip LEDs with AlInGaP active material are developed, then multi-color lighting is enabled, but manufacturing process compatibility must be maintained
Solution Approach 1:
The patent modifies the active material layer composition parameter to achieve different wavelength emissions. By adjusting the AlInGaP composition ratios, the LED can emit red light (550-650 nm) while maintaining compatibility with existing flip chip manufacturing processes. The same basic fabrication steps are used, only the material composition parameter changes.
3Ease of operation
If electrical terminals are positioned along a common surface, then electrical connection with contacts on opposed surface is facilitated, but electrical isolation between terminals must be maintained
Solution Approach 1:
The patent introduces an insulating layer as an intermediary between the first and second electrical terminals that are positioned along the same surface. This insulating barrier prevents electrical shorting between terminals while allowing both terminals to access the active material layer for current injection. The insulating layer acts as a mediator that enables surface mounting while maintaining electrical isolation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables multi-color lighting applications by integrating red flip chip LEDs with existing LED architectures, enhancing assembly efficiency and optical performance.
Implementation Method 1
an active material layer bonded to the carrier and emitting light having a wavelength of from about 550 to 650 nm
Implementation Method 2
The flip chip LEDs are covered with a phosphorus material comprising a yellow constituent
Data Source
AI summary
Flip chip LEDs comprise a transparent carrier and an active material layer such as AlInGaP bonded to the carrier and that emits light between about 550 to 650 nm. The flip chip LED has a first electrical terminal in contact with a first region of the active material layer, and a second electrical terminal in contact with a second region of the active material layer, wherein the first and second electrical terminals are positioned along a common surface of the active material layer. Chip-on-board LED packages comprise a plurality of the flip chip LEDs with respective first and second electrical terminals interconnected with one another. The package may include Flip chip LEDs that emit light between 420 to 500 nm, and the flip chip LEDs are covered with a phosphorus material comprising a yellow constituent, and may comprise a transparent material disposed over the phosphorus material.